diff --git a/pkgs/by-name/pm/pmacct/package.nix b/pkgs/by-name/pm/pmacct/package.nix
index 491735246210..e58d1558dd26 100644
--- a/pkgs/by-name/pm/pmacct/package.nix
+++ b/pkgs/by-name/pm/pmacct/package.nix
@@ -68,7 +68,7 @@ stdenv.mkDerivation (finalAttrs: {
   ]
   ++ lib.optional gnutlsSupport gnutls;
 
-  MYSQL_CONFIG = lib.optionalString withMysql "${lib.getDev libmysqlclient}/bin/mysql_config";
+  env.MYSQL_CONFIG = lib.optionalString withMysql "${lib.getDev libmysqlclient}/bin/mysql_config";
 
   configureFlags = [
     "--with-pcap-includes=${libpcap}/include"